Teres Minor

Origin, Insertion, Action, Innervation

Origin: Upper two-thirds of the lateral (axillary) border of the scapula
Insertion: Inferior facet of the greater tuberosity of the humerus, posterior shoulder joint capsule
Action:
Primary: Lateral (external) rotation of the shoulder
Horizontal abduction (minor)
Compression of the humeral head into the glenoid (dynamic stabilization)
Inferior depression of the humeral head during abduction
Innervation: Axillary nerve (C5–C6)

Palpation Guide

Client position: Prone or seated.
Landmark sequence:

Locate the lateral (axillary) border of the scapula — palpate the edge of the scapula from the inferior angle superiorly.
Teres minor lies along the upper two-thirds of this border, between the infraspinatus above and teres major below.
The key landmark for distinguishing teres minor from teres major: teres minor is superior and inserts on the greater tuberosity (lateral rotation), while teres major is inferior and inserts on the anterior humerus (medial rotation).
Palpate a thin band of muscle along the lateral border, deep to the posterior deltoid laterally.

Tissue feel: Thin and cord-like compared to the broader infraspinatus above it. It lies on the lateral scapular border like a narrow strap. In a hypertonic state, it feels like a taut rope along the border.
Confirmation test: Ask the client to laterally rotate the shoulder against resistance with the arm at the side. Both teres minor and infraspinatus contract. To bias teres minor, resist lateral rotation with the arm slightly abducted (at 90° abduction — the hornblower's position) — weakness here implicates teres minor specifically.
Common errors:
Confusing teres minor with teres major — they lie adjacent on the lateral scapular border but have opposite rotational actions (minor = lateral rotation, major = medial rotation).
Confusing teres minor with the inferior portion of infraspinatus — the two are difficult to distinguish by palpation alone. Functionally, they work together.
Missing teres minor beneath the posterior deltoid — the lateral portion is covered by the deltoid.

Trigger Point Referral

Common TrP locations: The primary TrP is in the mid-belly, along the lateral border of the scapula at approximately the junction of the upper and middle thirds of the border.
Referral pattern: Refers to a small, sharply defined area at the posterior deltoid region. May also refer deep into the posterior shoulder joint.
Clinical significance: The localized posterior shoulder referral is easily confused with posterior glenohumeral joint pathology. If the client reports a deep posterior shoulder ache that worsens with reaching overhead, palpate the lateral scapular border for teres minor TrPs before assuming joint-level pathology.

Trigger point referral diagram — coming soon

Image coming soon. For visual reference, see [Teres Minor at TriggerPoints.net](http://www.triggerpoints.net/muscle/teres-minor).

Clinical Notes

Innervation significance:

The axillary nerve (C5–C6) innervates both teres minor and the deltoid. It passes through the quadrilateral space (bordered by teres minor superiorly, teres major inferiorly, long head of triceps medially, and surgical neck of humerus laterally). Compression of the axillary nerve in the quadrilateral space can produce selective teres minor and deltoid weakness.

Common conditions:

Involved in conditions/rotator-cuff-tendinopathy as part of the rotator cuff group, though it is less commonly torn than the supraspinatus.
Contributes to posterior glenohumeral stability — weakness of teres minor and infraspinatus allows anterior humeral head translation, contributing to conditions/shoulder-instability.
Quadrilateral space syndrome — compression of the axillary nerve in the quadrilateral space produces teres minor and deltoid weakness with posterior shoulder pain.
In overhead athletes, teres minor is eccentrically loaded during the deceleration phase of throwing, alongside infraspinatus.

What you'll typically find:

Teres minor is clinically inseparable from infraspinatus in most treatment sessions — the two are assessed and treated together as the lateral rotator pair. Both are usually hypertonic and harbor TrPs in clients with shoulder dysfunction.
Isolated teres minor pathology is uncommon. When it is the primary issue, the presentation is a deep, localized posterior shoulder ache that does not spread down the arm (unlike infraspinatus, which refers anteriorly and distally).

Treatment effects:

Sustained compression along the lateral scapular border is effective. Position the client prone and palpate the border, applying compression to tender points for 30–60 seconds.
Longitudinal stripping along the lateral border from the inferior angle toward the greater tuberosity treats both teres minor and the inferior infraspinatus fibers.
Post-treatment, lateral rotation strength and ROM typically improve alongside infraspinatus release.

Cautions:

The axillary nerve and posterior circumflex humeral artery pass through the quadrilateral space immediately adjacent to teres minor. Avoid deep sustained pressure in the quadrilateral space (the area just lateral to the long head of the triceps, inferior to teres minor, and superior to teres major).
The long thoracic nerve runs along the lateral thoracic wall deep to the scapula — not directly related to teres minor treatment but is in the region during lateral scapular border work.

Clinical pearl:

Teres minor and teres major are often confused in anatomy class because of their adjacent positions on the lateral scapular border. The clinical mnemonic is: minor rotates laterally (external), major rotates medially (internal). If you resist lateral rotation and feel a contraction along the upper lateral border, you are on teres minor. If you resist medial rotation and feel contraction along the lower lateral border, you are on teres major.

Assessment

Manual muscle testing:

Lateral (external) rotation: Same test as infraspinatus — resisted lateral rotation with arm at side, elbow at 90°. Tests both teres minor and infraspinatus together.
Hornblower's position: Arm abducted to 90°, elbow flexed to 90°. Ask the client to laterally rotate against resistance. Inability to hold this position (the arm falls into internal rotation) specifically suggests teres minor or infraspinatus tear.

Stretch test:

Internal rotation (hand behind back): Same as infraspinatus. Restriction in internal rotation indicates shortening of the lateral rotator group (infraspinatus and teres minor).

Related special orthopedic tests:

Hornblower's sign — specifically tests teres minor/infraspinatus integrity at 90° abduction
Lateral rotation lag sign — the arm cannot maintain the laterally rotated position when released

Muscle Groups

Rotator cuff (anatomical):

Lateral (external) rotators of the shoulder (functional):

anatomy/muscles/infraspinatus — primary lateral rotator
Teres minor (this article)
anatomy/muscles/deltoid — posterior fibers (minor)

Axillary nerve group (innervation):

anatomy/muscles/deltoid
Teres minor (this article)

Related Muscles

Synergists for lateral rotation:

anatomy/muscles/infraspinatus — primary synergist; the two function as a lateral rotator pair

Antagonists:

anatomy/muscles/subscapularis — primary medial rotator
anatomy/muscles/teres-major — adjacent on the lateral border but opposite action (medial rotation)
anatomy/muscles/pectoralis-major — medial rotator

Same innervation (axillary nerve):

anatomy/muscles/deltoid — shares C5–C6 axillary nerve; both affected in quadrilateral space syndrome

Key Takeaways

Clinically inseparable from infraspinatus in most treatment sessions — the two form the lateral rotator pair and are assessed together.
Localized posterior shoulder referral distinguishes it from infraspinatus (which refers anteriorly down the arm).
The axillary nerve passes through the quadrilateral space immediately adjacent — deep pressure here risks nerve compression.